Many electronic tube devices are hermetically sealed to protect delicate internal components from corrosion and other environmental effects that reduce the life of the tube and degrade its performance. However, it can often be difficult to detect small leaks in a hermetic seal, allowing defective electronic tube devices to be incorporated into larger electronic systems and sold to a customer. Over time, as more and more of the outside environment leaks into the tube device causing the tube to degrade, the performance of the larger system degrades.
Existing techniques for determining leaks in a hermetic seal include the use of a radioactive tracer gas that is used to fill a test chamber. The electronic tube device is then placed within the chamber allowing the tracer gas to enter the device. The device is then removed from the chamber and tested for the presence of the radioactive tracer gas. However, this can require the destruction of the electronic tube device, thus rendering the method unsuitable for 100 percent sampling. Further, the use of a radioactive gas also raises environmental health and safety concerns.